1. Field of the Invention
The technical scope of the invention is that of deployment devices for the control surfaces of projectiles.
2. Disclosure of the Related Art
So as to ensure the greatest possible accuracy of modern ballistic or propelled projectiles, these are equipped with control surfaces to correct their trajectory or to stabilize them. These control surfaces are piloted by electric motors. Given the space taken up by these control surfaces, these are generally contained within the projectile body during the handling phase and when being put in place in a gun barrel as well as during the interior ballistics phase. The control surfaces are then deployed in flight.
Patent EP-1550837 proposes to deploy the control surfaces by using springs individually equipping each control surface. This device suffers a major drawback. So as not to comprise the stability of the projectile, it is essential for the deployment of all the control surfaces to be simultaneous, this device, however, cannot guarantee this since the springs act independently of one another. Because of this, any differences in the elasticity or of any other mechanical characteristic of the springs risks causing the control surfaces to deploy at slightly different times from one another.
Patent FR-1328459 discloses a device to simultaneously deploy the tail fins of a rocket. The fins are deployed by means of toothed sectors integral with the control surfaces and meshing with a toothed-rack ring. A single toothed-rack ring ensures the simultaneous deployment of the fins.
Similarly, patent DE-3838735 discloses a device to simultaneously deploy fins. As in FR1328459, this device requires a single sliding element incorporating toothing around its periphery and meshing with pinions at the base of the control surfaces.
The drawback to these solutions lies in that the toothed ring prevents the fin from pivoting after its deployment. These solutions are thus unsuitable for the deployment of control surfaces intended to be pivoted by a motor after their deployment to ensure the piloting of the projectile.
U.S. Pat. No. 6,880,780 discloses a device to deploy control surfaces by means of lever arms also acting as locking means for the control surfaces in their retracted position. Such a device is however particularly cumbersome axially and is difficult to integrate into a projectile. It is reserved for large-sized projectiles, such as missiles.